The smallest modern gas engines are MVVS. I think they have one around 1.60. There are old technology engines around .60. You can get them as new reproductions. They do not have a lot of power. If you are looking for say a 60 gasser that would fly a plane today I would say you are out of luck. Gasoline just does not work well in that small an engine. You are better off with a glow engine. Untill you get to 1.5 or bigger it is just not feasable. Good luck.

Mark Shuman